Core exerciser



FIG. 1 is a front perspective view of the core exerciser, showing my new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a right side view, the left side being a mirror image thereof;

FIG. 4 is a front view, the back view being a mirror image thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a top view thereof.

The broken lines shown in the figures are for the purpose of illustrating portions of the core exerciser, which form no part of the claimed design. 

CLAIM The ornamental design for a core exerciser, as shown and described. 